Examples of prior push-button switches are disclosed in the above-referenced U.S. Pat. No. 5,201,410 (hereinafter "the '410 patent"). In this regard, the push-button switches of the '410 patent include a housing having opposed pairs of side walls defining an interior space, and an opposed pair of fixed contact members. A push-button assembly is received within the interior space of the housing for reciprocal movements between extended and retracted positions. The push-button assembly includes a pair of opposed side windows having lower extents established by a bridge wall. A spring exerts a bias force to move the push-button assembly into its extended position.
A generally inverted V-shaped slide contact member is movable with the push-button assembly between its extended and retracted positions, and includes a pair of resilient legs each having an outwardly curved contact region. The contact regions serve to contact the pair of fixed contact members when the push-button assembly is moved into one of its extended and retracted positions whereby an electrical circuit is made, and breaks contact with at least one of the fixed pair of contacts when the push-button assembly is moved into the other of its extended and retracted positions, whereby an electrical circuit is broken. The slide contact member further includes terminal end flanges extending from the curved contact regions, the terminal end flanges being positioned so as to contact a respective bridge wall of an associated side window and thereby limit the extent of outward resilient displacement of the legs of the slide contact member.
Although the prior push-button switch as described above exhibits many desirable attributes, there have still been problems in assembly of some component parts, namely the fixed contact members and the spring. In this regard, it will be noted in the '410 patent that the fixed contact members are asymmetrical--that is, one generally L-shaped and one generally planar fixed contact members are provided. By virtue of this asymmetry, therefore, automated operations (e.g., the press-fit mounting of both fixed contact members within the housing) are made more complex and difficult. Furthermore, the coiled diameter of the bias spring is substantially less as compared to the diameter of the interior housing space in which it is received. As a result, the spring has a tendency to twist and/or bend into undesirable shapes during assembly of the switch components thereby raising the possibility of assembly errors causing defective switches to be produced.
It is a principal object of this invention, therefore, to provide push-button switch structures which remedy the problems noted above. Therefore, broadly, the present invention relates to novel spring-biased push-button switches having component structures which facilitates ease of assembly and thus are conducive to assembly by automated means (e.g., assembly robots).